With the development of society, more and more users use the communication devices and means of communication also become more diversified, from the original fixed telephone to the current mobile phone, and the consumers of various industries and regions are involved. The mobile phone products greatly facilitate people's lives and make the communication become more convenient. Currently, the main advantage of mobile phone is the mobility, but the users usually put the mobile phones aside and then go to do something else when going home or going to some fixed places after work, thus a problem of missing calls due to failure to hear the ringing of incoming calls exists. Similarly, there is also a phenomenon of the consumers missing calls due to failure to hear the ringing of mobile phone in certain places at home.
“GBT 15629.11(1102)-2003” discloses a WLAN Authentication and Privacy Infrastructure (WAPI) which is composed of a WLAN Authentication Infrastructure (WAI) and a WLAN Privacy Infrastructure (WPI). The WAI is a basis for implementing the WAPI. With the WAI, in a BSS, when a STA associates or re-associates with an AP, an authentication with each other should be performed; if the authentication is completed, the AP allows for accessing of the STA. The whole authentication process includes a certification authentication, a unicast key negotiation and a broadcast key notification, which is shown in FIG. 4.